1. Field of the Invention
This invention relates generally to semiconductor manufacturing, and, more particularly, to a method and apparatus for adjusting the rate of data flow based upon tool state(s).
2. Description of the Related Art
The technology explosion in the manufacturing industry has resulted in many new and innovative manufacturing processes. Today""s manufacturing processes, particularly semiconductor manufacturing processes, call for a large number of important steps. These process steps are usually vital, and therefore, require a number of inputs that are generally fine-tuned to maintain proper manufacturing control.
The manufacture of semiconductor devices requires a number of discrete process steps to create a packaged semiconductor device from raw semiconductor material. The various processes, from the initial growth of the semiconductor material, the slicing of the semiconductor crystal into individual wafers, the fabrication stages (etching, doping, ion implanting, or the like), to the packaging and final testing of the completed device, are so different from one another and specialized that the processes may be performed in different manufacturing locations that contain different control schemes.
Generally, a set of processing steps is performed across a group of semiconductor wafers, sometimes referred to as a lot. For example, a process layer that may be composed of a variety of different materials may be formed across a semiconductor wafer. Thereafter, a patterned layer of photoresist may be formed across the process layer using known photolithography techniques. Typically, an etch process is then performed across the process layer using the patterned layer of photoresist as a mask. This etching process results in the formation of various features or objects in the process layer. Such features may be used as, for example, a gate electrode structure for transistors. Many times, trench isolation structures are also formed across the substrate of the semiconductor wafer to isolate electrical areas across a semiconductor wafer. One example of an isolation structure that can be used is a shallow trench isolation (STI) structure.
The manufacturing tools within a semiconductor manufacturing facility typically communicate with a manufacturing framework or a network of processing modules. Each manufacturing tool is generally connected to an equipment interface. The equipment interface is connected to a machine interface to which a manufacturing network is connected, thereby facilitating communications between the manufacturing tool and the manufacturing framework. The machine interface can generally be part of an advanced process control (APC) system. The APC system initiates a control script, which can be a software program that automatically retrieves the data needed to execute a manufacturing process.
FIG. 1 illustrates a typical semiconductor wafer 105. The semiconductor wafer 105 typically includes a plurality of individual semiconductor die 103 arranged in a grid 150. Using known photolithography processes and equipment, a patterned layer of photoresist may be formed across one or more process layers that are to be patterned. As part of the photolithography process, an exposure process is typically performed by a stepper on approximately one to four die 103 locations at a time, depending on the specific photomask employed. The patterned photoresist layer can be used as a mask during etching processes, wet or dry, performed on the underlying layer or layers of material, e.g., a layer of polysilicon, metal or insulating material, to transfer the desired pattern to the underlying layer. The patterned layer of photoresist is comprised of a plurality of features, e.g., line-type features or opening-type features that are to be replicated in an underlying process layer.
Turning now to FIG. 2, a flow chart depiction of a prior art process flow is illustrated. A manufacturing system processes semiconductor wafers 105 in a batch/lot (block 210). Upon processing of semiconductor wafers 105, the manufacturing system may generally acquire tool state data relating to the processing tools that were used to perform the processes (block 220). The tool state data may be acquired using a data acquisition schedule that is determined prior to processing the semiconductor wafers 105. For example, a predetermined data rate for acquiring tool state data relating to processing of semiconductor wafers 105 may be employed in the acquisition of tool state data. Based upon the acquired data, the manufacturing system may perform fault detection analysis (block 230). Based upon the fault detection analysis, the manufacturing system may adjust the operation of one or more processing tools based upon the corrections deemed required to reduce faults (block 240).
One problem associated with employing the current methodology includes the fact that generally, a common predetermined data rate is used to acquire tool state data relating to processing of semiconductor wafers 105. Utilizing a common data rate may provide tool state data that may not be tailored to particular process steps performed on the semiconductor wafers 105. For example, capturing useful tool state data relating to certain processes may require a different data acquisition rate as compared to other processes. Additionally, predetermined common data collection rates that are employed in current processing operations may not react adequately to changes that may occur in the process. Therefore, a lack of adjustability in acquiring tool state data may lead to inadequate acquisition of tool state data, which may result in inadequate or non-optimal fault detection analysis. This may lead to processing errors that may result in inferior semiconductor wafers 105.
The present invention is directed to overcoming, or at least reducing, the effects of, one or more of the problems set forth above.
In one aspect of the present invention, a method is provided for adjusting a rate of data flow based upon a tool state. A processing step is performed on a workpiece using a processing tool. A dynamic data rate adjustment process is performed to determine a data rate for acquiring data relating to the process performed upon the workpiece. The dynamic data rate adjustment process includes adjusting the data rate based upon an operation parameter relating to the processing tool.
In another aspect of the present invention, a method is provided for adjusting a rate of data flow based upon a tool state. A processing step is performed on a workpiece using a processing tool. The data rate for acquiring tool state data is dynamically adjusted. The data rate is dynamically adjusted based upon a fault data, a recipe data, or a process step data relating to an operation of the processing tool.
In another aspect of the present invention, a system is provided for adjusting a rate of data flow based upon a tool state. The system includes a processing tool to process a workpiece. The system also includes a process controller operatively coupled to the processing tool. The process controller is capable of performing a dynamic data rate adjustment process to determine a data rate for acquiring data relating to performing a process upon the workpiece. The dynamic data rate adjustment process includes adjusting the data rate based upon an operation parameter relating to the processing tool.
In another aspect of the present invention, an apparatus is provided for adjusting a rate of data flow based upon a tool state. The apparatus includes a process controller adapted to perform a dynamic data rate adjustment process to determine a data rate for acquiring data relating to performing a process upon the workpiece using a processing tool. The dynamic data rate adjustment process includes adjusting the data based upon an operation parameter relating to the processing tool.
In yet another aspect of the present invention, a computer readable program storage device encoded with instructions is provided for adjusting a rate of data flow based upon a tool state. The computer readable program storage device encoded with instructions that, when executed by a computer, performs a method, which comprises: performing a process step upon a workpiece; performing a process step upon a workpiece using a processing tool; and performing a dynamic data rate adjustment process to determine a data rate for acquiring data relating to performing a process upon the workpiece. The dynamic data rate adjustment process includes adjusting the data rate based upon an operation parameter relating to the processing tool.